Canon: Tales of the Rays
Villain/Antag/Monster: Emperor Demitrius (final boss form)
Type: Boss
Description: There's no good wiki entry for his boss form so have a video
Notes/Adjustments: Given that he's utilizing Chronos' power, he can basically heal himself back up to full mid-fight as seen in the video. And then launch an MA right at your face Since Chronos doesn't exist here in Reverein, however, his powers on that front will likely be more limited than they are in canon in terms of being able to heal himself.
Will it exist after the event? Nope!
Questions/Other: Please kick his rear, he deserves it